Box strapping tool



Jan. 15, 1957 Filed Oct. 26, 1953 H. A. SMITH BOX STRAPPING TOOL SSheets-Sheet 1 INVENTOR. HARRY A. SM/TH TORNEYJ 7 1957v 7 I H. A. SMITH2,777,344

BOX STRAPPING TOOL Filed Oct. 26, 1953 F/GS 5 SheetsSheet 2 INVENTOR.HARRY A. JM/TH A ORNEYJ Jan. 15, 1957 Filed Oct. 26, 1955 H. A. SMITH2,777,344

BOX STRAPPING FOOL 3 Sheets-Sheet 3 INVENTOR.

HAPPY A .SM/ TH BY l TTORNE Y5 BOX STRAPPING TOOL Harry A. Smith,Middletown, Conn., assignor to The Stanley Works, New Britain, Conn., acorporation of Connecticut Application October 26, 1953, Serial No.388,409

6 Claims. (Cl. 81-9.1)

The present invention relates to an improved box strapping tool fortensioning and sealing metal straps about boxes, packages and the like,and more particularly to such a tool employing a magazine for carrying astack of seals, and having improved means for jamproof feeding of theseals from the magazine to the sealing mechanism.

It is an object of the present invention to provide a box strapping toolof the aforesaid type wherein accidental feeding of seals from themagazine is substantially preeluded.

Another object is to provide a box strapping tool of the aforesaid typehaving a sealing mechanism operated by means of a single control handle,wherein the means for feeding seals to the sealing mechanism can beoperated only by a deliberate excursion of the control handle throughits full displacement.

Another object of the present invention is to provide a box strappingtool of the aforesaid type, so constructed and arranged that only asingle seal feeding operation can take place during any one strapsealing cycle.

Another object is to provide a box strapping tool of the aforesaid typewherein means isprovided to insure that only one seal can be extractedfrom the magazine and delivered to the sealing mechanism during a singlesealing cycle.

Another object is to provide an improved box strapping tool of theaforesaid type in which the means for feeding seals from the magazine tothe sealing mechanism can be operated only in response to a concurrentoperation of the sealing mechanism to deform and discharge any sealstherein.

Another object is to provide a box strapping tool of the aforesaid typehaving improved means for automatically aligning the strapping materialtherein.

Other objects will be in part obvious and in part pointed out more indetail hereinafter.

The invention accordingly consists in the features of construction,combination of elements and arrangement of parts which will beexemplified in the construction hereafter set forth and the scope of theapplication of which will be indicated in the appended claims.

In the drawings:

Figure 1 is a side view of a box strapping tool constructed inaccordance with the present invention, showing its disposition relativeto an article to be strapped, and showing the general organization ofcertain of the operating parts thereof;

Fig. 2 is a view similar to Fig. l with certain exterior portions of thetool cut away to expose additional operating parts thereof;

Fig. 3 is an enlarged view of the tool showing the side opposite to thatshown in Figs. 1 and 2, and also partially cut away to show details ofcertain of the internal parts;

Fig. 4 is a sectional view taken on the line 4--4 of Fig. 3;

Fig. 5 is an enlarged view of the side of the tool shown nited StatesPatent 0 "ice in Figs. 1 and 2, cut away to show additional details ofthe internal structure of the tool; and

Fig. 6 is a sectional view of the tool shown in Fig. 5, taken on theline 6-6 thereof.

Referring to the drawings, wherein like reference characters denote likeparts in the several views, a box strapping tool constructed inaccordance with the present invention includes a frame 2 which carries astrap tensioning mechanism 4, a strap sealing mechanism 6, a sealmagazine 8, a seal feeding mechanism 10, and a single sealing handle 12for manually controlling the operation of the sealing mechanism 6, andin association with it the operation of the seal feeding mechanism 10.

The frame 2 is provided with a base 14, including a plurality oflaterally extending feet 16, 18 which are adapted to rest, as shown inFig. 1, on the box or article to be strapped. Above and adjacent one ofthe feet 16 there is provided in the frame 2 a strap receiving andaligning channel 20 through which the free end of the strapping materialcarried on an adjacent supply reel or spool, not shown, is fed beforebeing passed around the box. A sufiicient length of strap is passedthrough this channel 20 to encircle the box, and the free end is thenpassed through another aligned channel 22 provided adjacent the otherfoot 18. On the first foot 16 is a shoulder 24 against which the freeend of the strap is adapted to abut to insure adequate overlap of thestrap for a proper sealing operation.

On the forward part of the frame 2 there is provided a strap tensioningmechanism 4 which includes a shaft 26 journaled in a trunnion 28 whichis pivotally mounted in the frame on another shaft 30. The shaft 26carries at one end, as shown in Fig. l, the usual strap tightening wheel32 having peripheral teeth 34 aligned with the strap receiving channel20, and adapted to engage the strap and draw it tight about the box.Connected to the trunnion 28 is a downwardly extending strap guide 36which assists in aligning the strap in the channel 20.

On the other end of the shaft 26 is mounted the tensioning handle 38,the manual operation of which in a clockwise direction, as shown in Fig.1, rotates the tightening wheel 32 and tensions the strap. Theconnection between the handle and the shaft 26 carrying the tighteningwheel 32 is of the usual ratchet and pawl type, not shown, so as toprevent retrograde movement of the tightening wheel 32 and loss oftension in the strap.

A spring 40 acting between the frame 2 and the trunnion 28 provides astrong bias of the trunnion 28 counterclockwise, as shown in Fig. 1, soas to urge the tightening wheel 32 normally into engagement with a strapin the channel 21}. However, the spring 40 is made of such a strengththat, when the tensioning handle 38 has been depressed far enough toprovide adequate tension in the strap, further depression of thetensioning handle 38 pivots the entire tightening wheel 32, shaft 26 andtrunnion assembly about the shaft 30, and thus disengages the tighteningwheel 32 from the strap in the channel 20. This has the dual purpose ofpreventing excessive tightening of the strap which might cause strapfailure, and of enabling release of the strap from the tool after a boxstrapping operation has been completed.

Rearwardly of the strap tensioning mechanism 4 there is provided on theframe adjacent the second strap aligning channel 22 a strap engaging dog42 pivotally mounted at 44 and urged by a biasing spring 46 clockwise,as

shown in Fig. 5, into strap engaging relation with the strap aligningchannel 22. Depending from the bottom face 48 of the dog 42 are aplurality of strap engaging teeth 50, which are positioned forward of aperpendicular from the strap through the axis of rotation of the dog 42,so that, as the strap is tensioned, any slippage of the cams 1%, 163have respective coaxial shanks strap will tend to rotate the dog 42further clockwise, as shown in Pig. 5, and more securely engage theteeth 55 with Silfi1 When the f ee end of the strap is being passedabout the box and being fed through the channel 22, the dog may beraised clear of the channel by actuation of a lever 52 which is providedat its outer end with a manual depression key 5 Carried by the dog 42 isone-half of a shear 56, the other half of which is carried by thesealing mechanism 5, as will later be described, for severing the boxencompassing portion of the strap from the supply reel.

The upper face of the lateral foot 's provided with a slight slope orinclination relative to the lower face 4-8 of the dog. and these twoopposed faces thereby form a tapered channel or slot, the apex of whichis disposed adjacent the strap receiving channel 22. This tapered slotacts in the manner of a funnel and assists in guiding the strap into thechannel 22. Also projecting from the lower face 4% of the dog 42-, toone side of the teeth 5d and opp e the inclined face of the foot 1 :3,is a strap alignin" mer er Tl 5: foot 18 is provided with a recessedportion into which the strap aligning member 60 is received when the dog4-2 is pivoted into engagement with the strap.

The function of the strap aligning member 60 is twofold. if strap is notproperly aligned in the channel 22, so that part of the strap extendsbeyond the side of the channel and rests on inclined face 58 of foot 13,when depression key 54 is released and dog 4?; descends toward thestrap, stra aligning member 69 will engage the strap before teeth h...of dog and thereby prevent locking engagement of the dog teeth 56 withthe strap. This permits the strap to be slid beneath dog 42 during thestrap tightening operation, and during such sliding of the strapaligning member 6% performs its second function by assisting in cammingthe strap completely into channel 22. When the strap is properly alignedin channel 22 it no longer engages strap aligning member 60, and therebydog 42. is permitted to descend fully and engage teeth 50 with thestrap.

The seal magazine 8 consists of a vertical arcuatc element 70, disposedon the forward part of the frame, and formed of hollow rectangular crosssection. The upper end of element 752 may be conveniently formed into ahandle '72. for carrying the tool. The seals in the megazine 8 are ofgenerally channel or inverted U-shape in cross section and have slopingsides so as to be carried in loosely nested relation in the magazine 8.

The sealing mechanism 6 includes a pair of arms 74 '76 pivotallysupported in the frame at 78 and carrying the scaling jaw assembly till.Arms 74, 76 are biased upwardly to a rest position, as shown in Figure2, by spring 82. The sealing jaw assembly 80 is of the usual doublepivoted toggle type, having jaws 86 which are normally biased to an openposition by springs 83 which embrace the jaw assembly. in operation inthe usual manner, the jaws 86 in closing fold or deform the sides of aseal inwardly under the top of seal. This reduces the width of the sealso that when the jaws 35 are opened, they can be withdrawn from aboutthe scaled strap or, in the absence of a strap, the deformed seal willfall out of the jaw assembly 80. To the upper portion of the jawassembly 80 is connected 0. link 92 which is slidably secured by pin 92and slot 94 to a lever 96. One end of lever 96 is pinned on a shaft 98journalcd in the frame 2.

The other end of lever 96 is fastened by means of a strap 1% to theouter ends of a pair of transversely spaced cranks 102, ill-i, each ofwhich is supported on one of a pair of spaced cams 2.06, 108. The twospaced 116*, 112 projecting from their outer sides which rotatablysupport the assembled cams lids, 16-3 and cranks 107;, 104 in the frame2 for rotation about axis 116. The cams 1G6, 168 are of generallysemicircular shape and coast with cam followers 12@ on the sides of therespective arms 74, "1'6 for depression of the arms and the sealing jawassembly 'side of the magazine 3.

4 30 carried by them. Rotation of the cams 1G6, 163 and the cranks N2,10 is accomplished by means of the sealing handle 12, which is securedto the shank 1 0 on the opposite side of the tool from the tensioninghandle 38.

The initial or rest position of the sealing handle 12, corresponding tothe rest position of the sealing mechanism 6, is, as shown in Fi ure 2,at the front of the tool. The handle 12 is maintained in this positionagainst a stop member, not shown, by means of the spring 33L, one end ofwhich is pinned to one of the arms "/6 and the other end of which issecured to the shank ill on the opposite side of the frame from thesealing handle 12..

To operate the sealing mechanism 6, the scaling handle 12 is rotatedfrom its position at the front of the tool, as shown in Figure 2, to asubstantially diametrically opposite position at the back of. the tool.The resulting rotation of the cams 3G6, 103 first depresses arms 74, '76and dis places the scaling jaw assembly from its rest position down toits operative position in engagement with the top of the box between thefeet i6, 18, in which position the jaws 36 embrace the overlappedportion of the strap. On the rear face of the jaw assembly is a shear132 which coacts with sheer 56 on dog 42 to sever the box encirclingstrap portion from its supply reel as the jaw assembly 30 descends toits operative position.

Further rotation of earns 1.06, 103 as the sealing lever 12 is rotatedthrough the remainder of its nrcunte displacement thereafter servesmerely to rotate lever 96 about shaft 98 by means of cranks 182, M4 farenough to bottom pin 92 in slot 94- and depress the upper portion of jawassembly 89 relative to the jaws 86. This relative motion actuates thetoggle linkage in the jaw assembly and squeezes the strap ends together.A seal carried in the jaw assembly 8%) between jaws 86 will thereby bedeformed about the overlapped portion of the strap, thus securing thetensioned strap about the box in the usual manner.

The seal feeding mechanism 16) includes a seal feeding member or pusher146 which is formed with slots 148 adapted for sliding engagement in atrack 15% formed by a pair of opposed flanges 1512 supported from thelower Pivotally connected its its lower end to the seal feeding memberor pusher 146 is an actuating and latching link which is supported atits other end on shaft 98 for rotation and limited sliding movc- "lent.For this purpose the link 34% is provided with an L-shapcd slot l l-lhaving a longitudinal leg M2 and a transverse leg M4 in which the end ofthe shaft 93 is are-- commodated. The lower end of lever M0 and the sealpusher 146 are urged rearwardly of track 150 by spring 154, which isconnected at 256 to frame 2. When in its rearmost position on the track15%), the seal pusher 1-56 is adjacent the rest position of the scalingjaw assembly 30, in seal delivering relation therewith. The lever 140also carries a projection having a lower shoulder 158 and an uppershoulder 169, which shoulders are adapted to be engaged respectively bya COCliing finger 16d and a tripping finger 166 pinned on shaft 953 forrotation with lever 96 during operation of the sealing mechanism. Theend of the shaft 98 enclosed by the slot 141 in the lever 141i isprovided with a longitudinal concave cutout 170 disposed opposite theinner corner 172 of the slot M1, for a purpose explained hereinafter.

The operation of seal feeding mechanism it? will now be described. Asthe sealing handle 12 is rotated from the front to the back of the tooland the sealing jaws S5 descend to embrace the ends of the strap, theaccompanying rotation of the cams 1G6, 198 and cranks 132i, 154 aboutaxis 116 pivots lever 9d and rotates shaft 93. This brings lower finger164 into engagement with lower shoulder 153 on lever Mil. Since thelever 14") is sup ported for both rotation and sliding movement withrespect to shaft 98, and since the lower end of lever 140 is attached toseal pusher 14-6 and thereby constrained to slide along track 150, theengagement of lower finger 164 with lower shoulder 158 and subsequentcounterclockwise rotation of lower finger 164 with shaft 98 moves sealpusher 146 forward on track 150 beneath the lower most seal, to anextreme position at the forward side of magazine 8, as shown in Figure3.

The top of seal pusher 146 is shaped to conform with the channel-shapedcross section of the seals. The sides of the lowermost seal in magazine8 rest on flanges 152. The height of the rear edge of seal pusher 146above the flanges 152 is suflicient that, when once displaced toposition forward of magazine 8, seal pusher 146 is enabled to engagepositively the top of the lowermost seal for extraction thereof frommagazine 8 when seal pusher 146 is returned rearwardly along the track150. The top of seal pusher 146 has a slight slope, being lower at itsfront edge, so that it is cammed smoothly beneath the lowermost seal,raising the stack of seals in the magazine momentarily as it is carriedforward on track 150.

The fact that the lower end of lever 140 is constrained to move alongtrack 150 requires that lever 140 slide downwardly with respect to shaft98 when seal pusher 146 is moved forward. As the lower end of lever 140reaches its point of extreme forward displacement on track 150, theaction of lower finger 164 pushing up on lower shoulder 158 pivots lever140 about its lower end and seats shaft 98 into the transverse portion144 of the slot 141 in the lever, as shown in Figure 3. This actionserves to latch the seal feeding mechanism 10 in the cocked positionwhere seal pusher 146 is capable of extracting a seal from the magazine8.

It should be understood that, as will be apparent from a considerationof the structure shown in Figure 5, lever 140 cannot be moved from theposition shown in Figure to the position shown in Figure 3 until lever96 has been rotated sufficiently counterclockwise, during theaccompanying counterclockwise rotation of cams 106, 108 by sealinghandle 12, to engage lower shoulder 158 with lower finger 164 anddisplace seal pusher 146 forward on track 150 underneath and beyond thelowest seal. Displacement of seal pusher 146 this far forward on track150 can be accomplished only by rotation of sealing handle 12 throughits full arc from its initial forward position, as shown in Figure 2, toits rearwardmost position. Thus the sealing mechanism 6 must be fullyoperated and any seal therein deformed in the usual manner by theclosing of the sealing jaws 86 before seal pusher 146 is positioned farenough forward on the track to be capable of extracting a sea] from themagazine.

The forward displacement of the lower end of lever 140 along track 150stretches the spring 154 by which it is urged rearwardly of frame 2, andhence lever 140 is strongly biased rearwardly of track 150. However,seal pusher 146 is prevented from returning rearwardly on track 150because such motion requires an accompanying longitudinal sliding motionof latching lever 140 relative to the shaft 98 in order to shorten thedistance between the lower end of lever 140 and shaft 98 as theconstrained lower end of lever 140 returns along track 150. Thisnecessary sliding motion of lever 140 relative to shaft 98 is preventedby the seating of shaft 98 in the transverse portion 144 of the L-shapedslot 141 in lever 140.

As the sealing handle 12 is returned toward its forward position at theend of the sealing operation, the accompanying rotation of cams 106, 108permits spring 82 to raise arms 74, 76 and jaw assembly 80 away from thesealed straps, the jaws 86 simultaneously being opened by springs 88.This return motion of the sealing handle 12, however, does notimmediately move lever 140 out of the position shown in Figure 3,because the seating of shaft 98 in transverse slot 144 prevents thesliding of lever 140 relative to shaft 98 which such movementnecessarily entails.

As sealing handle 12 is returned further toward its forward position,the lever 96 is eventually rotated sufficiently so that,'as shown inFigure 3, upper finger 166 engages upper shoulder 160 on lever 140 andserves to pivot lever rearwardly about its lower end. At the same timethe shaft 98 becomes so rotatively aligned that the cutout portion 170receives the inner corner 172 of lever slot 141 and permits the lever140 to be pivoted enough for relative movement of the slot corner 1'72.across this cutout portion 170. This relative movement aligns thelongitudinal leg 142 of lever slot 141 with the shaft 98.

When so aligned, lever 140 can he slid upwardly relative to shaft 98,and this unlatches the seal feeding mechanism and enables spring 154 tomove the lower constrained end of lever 140 abruptly rearward alongtrack 150. This displaces seal pusher 146 rearwardly on track 150 towardthe sealing jaw assembly 80. In being so displaced, seal pusher 146engages the front end of the lowermost seal and carries it down track150 and into the seal receiving cavity between the jaws 86 of the jawassembly 80.

The arrangement of the elements is such that the upper finger 166 doesnot contact upper shoulder to begin pivoting lever 140 rearwardly aboutits lower end until the sealing handle 12, and with it the jaw assembly80, has been returned substantially completely from its operativeposition to its rest position. Thus it may be seen that it is aparticular feature of the present invention that seal feeding mechanism10 is rendered substantially foolproof by the requirement that thesealing handle 12 be rotated through the full arcuate displacementrequired to complete a strap sealing operation before the seal feedingmechanism 10 is enabled to extract a fresh seal from the magazine 8.And, even after the seal feeding mechanism 10 is thus positioned in sealextracting relation with the magazine 8, no seal can be withdrawn fromthe magazine until the sealing handle 12 has been returned almostcompletely to its initial rest position. This means that idle orspeculative oscillation of sealing handle 12 through anything less thana complete excursion between its initial rest position and itsapproximately diametrically opposite sealing position cannotaccidentally feed seals into the sealing jaw assembly 80. Since thesealing mechanism 10 will automatically be cycled through a completesealing operation in response to such an excursion of the sealing handle12, thereby deforming and discharging any seal previously held betweenthe sealing jaws 86, jamming of the sealing jaw assembly 80 by thefeeding of extra seals therein is precluded.

As many changes could be made in the above construction and manyapparently widely different embodiments of this invention could be madewithout departing from the scope thereof, it is intended that all mattercontained in the above description or shown in the accompanying drawingsshall be interpreted as illustrative and not in a limiting sense.

It is also to be understood that the language used in the followingclaims is intended to cover all of the generic and specific features ofthe invention herein described and all statements of the scope of theinvention which, as a matter of language, might be said to falltherebetween.

I claim as my invention:

1. In a box strapping tool of the type having a frame, a sealingmechanism supported in said frame for movement between a rest positionand a sealing position, a magazine on said frame carrying a stack ofseal members, a seal feeding member supported on said frame forreciprocation between a seal delivering position in align ment with therest position of said sealing mechanism and a seal extracting positionat said magazine, and a control handle for moving said sealing mechanismbetween its rest and sealing positions, linkage means interconnectingsaid sealing mechanism and seal feeding member for displacing saidfeeding member into said seal extracting position responsive to movementof said sealing mechanism to said sealing position, locking means onsaid linkage means for securing said feeding member in said extractingposition, and trip means connected to said linkage means and operativeto disengage said locking means to release said feeding member formovement from its seal extracting position to its seal deliveringposition responsive to movement of said sealing mechanism toward itsrest position.

2. In a box strapping tool of the type having a frame, a sealingmechanism mounted in said frame for movement between a rest position anda sealing position, an operating handle for movin said sealing mechanismbetween its rest and sealing positions, a magazine carrying a stack ofseal members, a seal feeding member supported for reciprocation beneaththe magazine between a seal extracting position and a seal deliveringposition, and means biasing the seal feeding member into seal deliveringposition, the combination comprising a link pivotally connected at oneend to the seal feeding member, a pivot member fixed relative to theframe pivotally and slidably connected to the other end of the link,means including a pivoted lever connected to the operating handle forpivoting the link to move the seal feeding member to seal extractingposition as the operating handle is moved to sealing position, latchingmeans including a shoulder on said link for preventing sliding movementof the link when the seal feeding member is in seal extracting position,and means connected to the pivoted lever for engagement with said linkto disengage said shoulder during movement of the operating handle tothe at rest position.

3. In a box strapping tool of the type having a frame, a sealingmechanism supported on the frame for movement between a rest positionand a sealing position and including sealing jaws for deforming a sealcontained therein when the mechanism is in sealing position, anoperating handle for moving said sealing mechanism between its rest andsealing positions and for actuating the jaws in sequence, a magazinecarrying a stack of seal members for successive alignment with thesealing jaws when the sealing mechanism is in its rest position, a sealfeeding member supported for straight-line reciprocating movementbeneath the magazine between a seal extracting position and a sealdelivering position. and means biasing the seal feeding member into sealdelivering position, the combination comprising a rotatable memberconnected to the operating handle for rotation thereby, a link pivotallyconnected at one end to the seal feeding member and pivotally andslidably mounted at its other end on said rotatable member, means onsaid rotatable member for pivoting the link in one direction to move theseal feeding member to seal extracting position when the operatinghandle is moved to the sealing position, a stop for preventing movementof the link in the other direction when the link is in its latterposition, and second means on the rotatable member to disengage the stopand permit movement of the link in said other other direction when theoperating handle is moved toward the rest position.

4. In a box strapping tool of the type having a frame, a sealingmechanism supported on the frame for movement between a rest positionand a sealing position and including sealing jaws for deforming a sealcontained therein when the mechanism is in sealing position, anoperating handle for moving said sealing mechanism between its rest andsealing positions and for actuating the jaws in sequence, a magazinecarrying a stack of seal members for successive alignment with thesealing jaws when the sealing mechanism is in its rest position, a sealfeeding member supported for straight-line reciprocating movementbeneath the magazine between a seal extracting position and a sealdelivering position, and means biasing the seal feeding member into sealdelivering position, the combination comprising a link pivotallyconnected at one end to the seal feeding member and having a L-shapedslot in its other end, said L-shaped slot having a longitudinal portionand a transverse portion, a fixed pivot engaged in said slot forsupporting said other end of the link for sliding and pivoting movementwhen engaged in the longitudinal portion and for pivoting movement onlywhen engaged in the transverse position of the slot, means actuated bythe handle pivoting the link to move the seal feeding member to sealextracting position and to engage the pivot in said transverse slot whenthe operating handle is moved to the sealing position, and second meansactuated by the handle for moving the link in an opposite direction todisengage the transverse slot from the pivot when, the operating handleis moved toward the rest position.

5. In a box strapping tool of the type having a frame, a sealingmechanism supported on the frame for movement between a rest positionand a sealing position and inc uding sealing jaws for deforming a sealcontained therein when the mechanism is in sealing position, anoperating handle for moving said sealing mechanism between its rest andsealing positions and for actuating the jaws in sequence, a magazinecarrying a stack of seal members for successive alignment with thesealing jaws when the sealing mechanism is in its rest position, a sealfeeding member supported for straight-line reciprocating movementbeneath the magazine between a seal extracting position and a sealdelivering position, and means biasing the seal feeding member into sealdelivering position, the combination comprising a rotatable shaftconnected to the operating handle, a link pivotally connected at one endto the seal feeding member and having an L-shaped slot in its other endembracing said shaft, said L-shaped slot having a longitudinal portionand a transverse portion, means mounted on said shaft for pivoting thelink to move the seal feeding member to seal extracting position and toengage the shaft in said transverse slot when the operating handle ismoved to the sealing position, and second means on the shaft for movingthe link in an opposite dircction to disengage the transverse slot fromthe shaft when the operating handle is moved toward the rest position.

6. in a box strapping tool of the type having a frame, a sealingmechanism supported on the frame for move ment between a rest positionand a sealing position and including sealing jaws for deforming a sea],contained therein when the mechanism is in sealing position, anoperating handle for moving said sealing mechanism between. its rest andsealing positions and for actuating the jaws in sequence, a magazinecarrying a stack of seal members for successive alignment with thesealing jaws when the sealing mechanism is in its rest position, a sealfeeding member supported for straight-line reciprocating movementbeneath the magazine between a seal extracting position and a sealdelivering position, and means biasing the seal feeding member into sealdelivering position, the combination comprising a rotatable shaftconnected to the operating handle, a link pivotally connected at one endto the seal feeding member and having an L-shaped slot in its other endembracing said shaft, said !.-shaped slot having a longitudinal portionand a transverse portion, a cooking finger fixed to said shaft andengageable with one side of the link for pivoting the link in adirection to move the seal feeding member to seal extracting positionand to engage the shaft in said transverse slot when the operatinghandle is moved to the sealing position, and a tripping finger fixed tothe shaft engageable with the other side of the link for moving the linkin an opposite direction to disengage the transverse slot from the shaftwhen the operating handle is moved in the opposite direction toward therest position.

References Cited in the file of this patent UNITED STATES PATENTS

